Steam engine



Apx'il 21, 1925.

,J. J. M ARDLE STEAM ENGINE Filed March 15, 1922 2 Sheets-Sheet 1JNVENTOR.

J. J. M ARDLE STEAM ENGINE Filed March 15, 1922 2 Sheets-Sheet 2Patented Apr. 21, 1925.

UNITED S ATES ra'rsivr @FFIQIE.

JAMES J. MCARIDLE, OF PAWTU'GKET, RHQDE ISLAND.

STEAM ENGINE.

Application filedMarch 15, 1922. Serial No. 543,847.

T 0 all whom it mag concern:

lie it known that 1, JAMES J. MoAnnLn, a citizen oftheUnited States,residing at Pawtucket, in the county of Providence and State of RhodeIsland, have invented new and useful Improvements in Steam Engines, ofwhich the following is a specification.

This invention relates to certain new and useiul improvements in steamengines, and

the primary object thereof is to provide means for eiiectingquickopening and closin of the intake valves and to simultaneously andquickly eilect opening and closing of the exhaust valves at the oppositeend of the cylinder upon each stroke oi the piston, so. as to therebyquickly relieve all possible back pressure on the piston when the steamenters the cylinder to effect operation of the piston.

A further object of the invention is to provide means for tripping theexhaust valves when the piston has completed its stroke and is about tocommence its return stroke. The invention further aims to provide anengine which has improved and. smipllfied means for performing the abovedescribed operations 01"" the valves.

Still further and other objects will be later set forth and manifestedin the course ofthe following description.

The invention more specifically resides in the comb nation of parts andthe construction thereof as will be now fully set forth. In the drawingsFigure 1 is a top plan viewoi" a steam ,ongine constructed in accordancewith the present invention; a

Figure 2 1s a side elevation;

tion.

In proceeding in accordance with the present invention a pair of gears 1and 2 are eccentrically mounted on the main drive shaft 3 of the engineand are in mesh with similar gears 1- and 5 respectively mounted on anarbor or stub shaft 6. Rockers 7 and 8 are pivoted at their lower endsto a pin 9 which latter is suitably secured to the base 10, rods 1.1 and12 being pivoted to the respective rockers and to the, respective gears4i and 5; The rockers are further connected by means of rods 13 and 14crespectively to wrist plates 15 and 16, the wrist plates being; arrangedone to the rear of the other and in register, and being loosely mountedon an arbor 17. The steam chest is designated 18,

Figure 3 is an enlarged detail side elevathe cross-head guide 19 and thepiston rod 20, the latter connected to the crank 21 of the main driveshaft 3. v

The several inletand exhaust valves are operater by in #21115 now to bedescribed. The inlet valves and 22 have arms 22 con- 'nected thereto,the latter being of a bell crank type, which are tensioned by rods 23 towhich springs 2e are connected, the

cams 2S and 29 to thereby etlect operation of p the latches'25 and 25.The exhaust valves Set and 353 have arms 36 and 3'? connected thereto,the arms carrying; pins 38 and 39 and having slotted outer ones 10 and11 in which pins 12 carried by s ringitensioned rods 4-3 and d3 aremounted. The rods 43 slide in brackets A; mounted on the steam chest,and the springs act to normally move the arms 36 and 37 outwardly totheir ver tical position. Latches 435 and 16 are pivoted at their innerends to the respective wrist plates 16 and 15 and are provided with stopshoulders 41 T and a8 and with cams 1E) and 50 the latter being forengagement with stationary cam trips 51 and 52 which may be suitablysecured to the base 10. The outer ends of the latches 15 and 4L6 areguided in slots provided therefore instantlards 53 and 54 that aresuitably secured to the base 10.

Inoperation, the wrist plates are operated by the rockers tarough thegear connections as described.- the intake valve 22 being. operated byvirtue of the shoulder 31 of the latch 25 striking pin 28, the latchbeing moved by the wrist plate in the direction of I the arrow of Figure3. Both intake latches move in the same direction. At the same timelatch 25 due to the slowingdown of the gear 5 is moving into positionfor engagementv of its shoulder '30 with the. pin 27. At the same timethat latch 25 is operating the valve 22" the shoulder 17 of latch 45 isengaging pin 38 to open the exhaust valve 3%, the latter being given avery quick movement since it is being operatedfrom the wrist plate 16,which latter is also operating the intake valve 22. lVhen the piston hascompleted its movement, then the latch is tripped by cam 51, releasingpin 38 from stop 47 whereupon the spring of rod 4-3 suddenly expandingforces the arm 36 and thereby valve 3% into closed position. The abovecycle of operation is repeated by the operation of the opposite set ofvalves-22 and 35 in the manner described in connection with the firstset. The springs 24k connected to the rods 23 serve to quickly move theintake valves 22' and 22 to closed position, as in the instance of thespring pressed rods 43 and a3 efi'ecting similar quick movement of theexhaust valves 34: and 35.

Having thus described my invention, what- I claim as new and desire tosecure by Letters Patent is 1. In a steam engine, a cylinder having aninlet and an exhaust valve at each end thereof, a pair of wrist platespivoted between their ends at points between the said pairs-of valves atthe ends of the cylinder, oppositely extending latches pivoted to thewrist plates and each having a stop shoulder and a cam thereon, therebeing a latch for each valve, spring pressed bell cranks connected tothe intake valves and having pins engageable with the stop shoulders toallow the latches to open the intake valves, cam trips for the latchesto operate the latter to eifect disengagement of the shoulders from thepins, slotted arms connected to the exhaust valves, and having pins toengage the stop shoulders of the latches thereof, spring pressed rodshaving pins engaged in the slots of the slotted arms for effectingclosing of the exhaust valves, rockers, rods pivoted to the rockers andto the wrist plates, pairs of intermeshing eccentric gears actuated bythe engine drive shaft, and rods pivoted to the gears and to therockers.

2. In a steam engine, a cylinder having an inlet and an exhaust valve ateach end thereof, a pair of wrist plates pivoted between their ends atpoints between the saie. pairs of valves at the ends of the cylinder,oppositely extending latches pivoted to the wrist plates and each havinga stop shoulder and a cam thereon, there being a latch for each valve,spring pressed bell cranks connected to the intake valves and havingpins engageable with the stop shoulders to allow the latches to open theintake valves, cam trips for the latches to operate the latter to eiiectdisengagement of the pins from the shoulders, slotted arms connected tothe exhaust valves, and having pins to engage the stop shoulders of thelatches thereof, spring pressed rods having pins engaged in the slots ofthe slotted arms for effecting closing of the exhaust valves, and meansoperated by the engine drive shaft to actuate the wrist plates.

3. In a steam engine, a cylinder having an inlet and an exhaust valve ateach end thereof, a pair of wrist plates pivoted be tween their ends atpoints between the said pairs of valves at the ends of the cylinder, alatch for each valve pivoted to the wrist plates and each having a stopand a cam thereon, spring pressed bell cranks connected to the intakevalves and having pins engageable with the stops to allow the latches toopen the intake valves, cam trips for the latches to operate the latterto ellect disengagement of th stops from the pins, arms connected to theexhaust valves and having pins engaging the stops, spring de vices foractuating the arms to close the exhaust valves, and means operated bythe engine drive shaft to actuate the wrist plates.

-l-. In a steam engine valve operating mechanism, a bell-crank leverconnected to one of the valves and having a vertically and ahorizontally disposed arm, 'a pin carried by the vertical arm of thelever, a spring connected to the horizontal arm of the lever, operatingmeans, a horizontal latch pivoted at one end to the operating meansandhaving its opposite end slidably supported on the pin, the latch havinga cam face and a shoulder, the latter engageable with the pin, and a camenga'geable with the cam face of the latch to raise the shoulder thereofup out of engagement with the pin.

5. In a steam engine valve operating mechanism, an arm connectedadjacent one end to one of the valves and extending upwardly therefrom,a slidable spring pressed rod having a pin and slot connection with theopposite free end of the arm, a pin on the arm between its ends, ahorizontal latch having a stop engageablewith the pin, means pivotallyconnected to the inner end of the latch to actuate the latter from theenginedrive shaft, cam means to actuate the latch to disengage the stopthereof from the pin, and means to slidably support the outer end of thelatch.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JAMES J. McAR-DLE.

